FAQ: unable to convert current value to float.

README.md

@@ -233,7 +233,25 @@ Then run build:
 
     make linux
 
-# Troubleshooting
+# FAQ/Troubleshooting
+
+## Unable to convert current value to float (metric=par,metri...in.go:285
+
+Oracle is trying to send a value that we cannot convert to float. This could be anything like 'UNLIMITED' or 'UNDEFINED' or 'WHATEVER'.
+
+In this case, you must handle this problem by testing it in the SQL request. Here an example available in default metrics:
+
+```toml
+[[metric]]
+context = "resource"
+labels = [ "resource_name" ]
+metricsdesc = { current_utilization= "Generic counter metric from v$resource_limit view in Oracle (current value).", limit_value="Generic counter metric from v$resource_limit view in Oracle (UNLIMITED: -1)." }
+request="SELECT resource_name,current_utilization,CASE WHEN TRIM(limit_value) LIKE 'UNLIMITED' THEN '-1' ELSE TRIM(limit_value) END as limit_value FROM v$resource_limit"
+```
+
+If the value of limite_value is 'UNLIMITED', the request send back the value -1.
+
+You can increase the log level (`-log.level debug`) in order to get the statement generating this error.
 
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